Multi-station work processing machine with variable carrier spacing



March 11, 1958 A. J. GIAIER 3 3 MULTI-STATION WORK, PROCESSING MACHINE IWITH VARIABLE CARRIER SPACING Filed May 10, 1957 4 Sheets-Sheet ;1

I INVENTQR.

Ali Gila J. G/fl/[R BY $41 March/11, 1958 A. J. GIAIER 2,826,288

- MULTI-STATION WORK PROCESSING MACHINE WITH VARIABLE CARRIER SPACINGFiled May 10, 1957 4 sheets-vSheec 2 INVENTOR. q/vsa 0 u. 674 AER 42:1iwzfwMw March 11, 1958 J, GIAIER 2,826,288

- MULTI-STATION WORK PROCESSING MACHINE WITH VARIABLE CARRIER SPACINGFiled May 10!, 1957 4 Sheets-Sheet 3 INVENTOR. 04 5.520 '1 G/A/[R ATia/Mfrs MULTI-STATION WORK PROCESSING MACHINE WITH VARIABLE CARRIERSPACING Angelo J. Giaier, Allen Park, Mich., assignor to George L.Nankervis Company, Detroit, Mich, a corporation of Michigan ApplicationMay 10, 1957, Serial No. 658,430

12 Claims. (Cl. 198-49) This invention relates to improvements in theconstruction of work processing machines of the type having a pluralityof work treating locations such as tanks. The invention will beillustrated in its application to a machine for electroplating workpieces.

Machines of the present type commonly employ a plurality of carrierseach having a vertically movable work supporting member, an elevator formoving selected work supporting members vertically and means foradvancing the carriers horizontally along a defined path of travelthrough the treating locations. A treating location may be a singlestation type having suflicient area to accommodate one carrier at atime, or a multi-station type where work supported from several carriersis treated simultaneously; The invention particularly applies to suchmachines wherein at least one work treating location is of themulti-station type.

The invention comprises an improved construction for mounting thecarriers and work supporting arms thereof and for varying the spacingbetween adjacent carriers so that the maximum number can besimultaneously positioned at a multi-station work treating location.

The invention includes track means on which the carriers are supportedfor free movement in a horizontal path. Drive means including a seriesof spaced pusher members are mounted for reciprocating horizontalmovement adjacent the path of carrier travel, and are reciprocated on adriving stroke at least equal in length to the longest increment oftravel required for advancing a carrier from one station to a successivestation. Each carrier includes a driven member engageable by one of thepusher members on the driving stroke only. Tripping means are employedfor disengaging the pusher and driven members before the end of thedriving stroke so that carriers can be advanced a shorter increment oftravel where desired. These tripping means are actuated in response tothe advance of a carrier by a pusher member to the position defined bythe location of the tripping means along the path of travel.

In machines employing a continuous loop path of travel, the improveddriving means includes means for advancing a carrier around the ends ofthe loop at decreased rates of acceleration and deceleration. As aresult, an increased rate of travel can be used along the straight sidesof the loop, decreasing the transfer time.

The improved carrier mounting includes upper and lower track memberswith means for supporting the carrier for free movement on one of thesetrack members and means for guiding it on both track members. Theguiding function is preferably performed in part at least by a guidingdevice which frictionally contacts at least one of the rail members tocontrol carrier deceleration and over-travel.

Over-travel is positively controlled by a suitable system of mechanicalstops, particularly at the work treating stations where over-travel mustbe limited.

Other features and advantages of the construction will be more fullyexplained in connection with the following atent Q p on a vertical axis,one at each end of the machine.

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description of the presently preferred embodiment of the inventionillustrated in the accompanying drawings which comprise:

Fig. 1, a perspective view of a machine incorporating the improvementsof the invention;

Fig. 2, an enlarged perspective view of the circled portion of Fig. 1with portions of the structure broken away for clarity;

Fig. 3, a perspective view of the carrier driving means;

Fig. 4, an enlarged side elevation of the driving elements for onecarrier; and

Fig. 5, a schematic view illustrating the operating cycle of the machineand the variable carrier spacing obtained.

Referring to Fig. l, the main framework is evident and comprisestransverse base members 10, 11 and vertical members 12 and 13 at eachend of the machine. These are connected by upper l4, 15, intermediate16, 17 and lower 18, 19 longitudinal members.

A plurality of carriers such as the carrier 20 are mounted for freehorizontal movement between upper and lower tracks 22 and 24 supportedby the framework as shown, the lower tracks resting upon members such asthe angle member 25. Each track consists of a pair of laterally spacedrails 26 and 27 which form horizontal and vertical supporting andguiding surfaces. In the construction shown, a carrier is supported by apair of wheels 28 rotatably carried by a base member 30 and engaging theupper surface of one of the lower rails 26. Vertically mounted guideblocks 34 are carried by an upper carrier member 36 and engagecorresponding surfaces of the upper track 22. A shoe 36 (Fig. 2) ispivotally secured to the carrier base member 319 and rides between therails of the lower track.

The carrier structure is completed by a pair of spaced angle members 37and 38 mounted to form facing V guide rails.

A Work supporting member 46 is secured to a carriage mounted forvertical movement on the guide rails 37 and 38, this carriage consistingof a plate 42 positioned alongside the guide rails and supportingV-groove guide wheels 43 and 44 intermediate the rails 37 and 38 (Fig.2).

An elevator, consisting of longitudinal and transverse frame members 46and 47, and fixed lifting rail sections 48 secured thereto. is mountedbetween the vertical end frame members 12 and 13, which serve as guides.Raising and lowering movement of the elevator is in response to theapplication of fluid pressure to an actuating cylinder 49, actingthrough a conventional system of chains 52 and counterweights (notshown). v

Each work supporting carriage is provided with a projecting liftingroller 54 for engagement by lifting rail sections of the elevator in amanner similar to that disclosed in U. S. Patent 2,605,882.

Movement of a carrier 20 along the path of travel is obtained from areciprocating type of driving arrangement, best shown in Figs. 1 and 3.A pair of shuttle bars 56 and 57 are located on each side of the looppath of travel below the lower track 24. Each shuttle bar is equippedwith guide wheels 58 which ride on a shuttle track 59 suspended from theouter rail member 26, as by members 60 and 6t. Sprockets 62 and 63 aremounted The axis of each of these sprockets is located between thecenter line 64 (Fig. 3) of the track and the curved track end.

The shuttle bars 56 and 57 are connected together by a chain 65 trainedabout the sprocket 62 and by a second chain 66 trained about thesprocket 63. Sprocket 62 is oscillated by a rotary type actuatingcylinder 67.

Each of the shuttle bars 56 and 57 is provided with a number of spacedpusher members 68 of circular shape. Each of these members has aprojecting dog 69 secured to it. The pusher members 68 act to advancecarriers along the straight sides of the loop track on reciprocatingmovement of the shuttle bars 56 and 57. Carrier movement around each endof the loop is provided by a set of auxiliary oscillating, one-waypusher bars 7% mounted on an axis coinciding with the center line 64 ofthe end of the loop track. These pusher bars "Fill are driven by a chain71 and set of sprockets '72 and 73, sprocket '72 being oscillated by theactuating cylinder 67 along with main sprocket 62. This auxiliary pusherarrangement reduces the acceleration imparted to a carrier moving aroundthe curved track ends and thus reduces swaying of a load supported bythe carrier.

A typical arrangement of work treating locations incorporated in amachine of this type is schematically shown in Fig. 5, the work treatinglocations being defined by tanks 75, 76 and 77. Tank 76 is large enoughto provide multiple carrier stations 78a, 78b and 730. The amount ofshuttle travel required in order to move a carrier from tank '75 to tank76 is shown by the distance 8%. The same amount of carrier movement isnot required in the multiple station tank '76. Instead, more carrierscan be simultaneously treated in this tank by reducing the increment acarrier is advanced with each. driving stroke of the shuttle.

Figs. 2 and 4 best illustrate the construction employed for obtainingsuch a reduced increment of movement. Each carrier is equipped with adepending pawl 82 mounted on a pivot pin 83 and projecting downwardlybetween the lower track rails 26 and 27 into overlapping relation with apusher bar for engagement by a pusher member 68 thereof.

A tripping cam 84 is provided at any work station where the amount ofcarrier travel from the preceding work station is less than the drivingstroke of the shuttle bars 56 and 57. This tripping cam 84 is pivotallysecured at to the outer track rail 26 and hangs down in pendulum fashioninto over-lapping relation with the pusher bar. A contact member 86projects inwardly from the cam 84 for engagement by the dog 69 of apusher member. This engagement, followed by further advancing movementof the pusher bar, pivots the cam 84 counterclockwise (as the parts areshown in Fig. 4) into engagement with an extension member 87 on the pawl82, thus moving the pawl upwardly and out of engagement with the pushermember 68. After the pusher member 68 and dog 69 have moved on, thetripping cam 84 and pawl 82 both swing back to their normal positions bygravity. During return movement of the pusher bars 56 and 57, the pushermembers 68 ride under the carrier pawls 82 which are tripped upwardlyand then return after the pushers have passed on.

The operating cycle of the machine is diagrammatically illustrated insequence in Fig. 5. In this view, the first position illustrated is thebeginning of the treatment period. The elevator has been lowered. Duringthe treatment period the shuttle is operated on its return stroke.

At the end of the treatment period the elevator is raised and the Worksupporting members of all carriers in single station tanks and anycarrier at the last station of a multi-station tank are lifted.

While the elevator remains in raised position, the shuttle is actuatedon its driving stroke to advance all carriers one position.

The elevator is then lowered with the shuttle held at the end of itsdriving stroke and the next treatment period begins.

In multi-station tanks, no elevator lifting rail is provided forpositions intermediate the entering and leaving stations. Once a carrierwork supporting arm is lowered into a multi-station tank the workremains in lowered position until the carrier reaches the last station.This operation is accomplished by the provision of a movable elevatorrail section 36 (Fig. l) at the entering station and a second movableelevator rail section 37 at the leaviug station. Movable rail section.86 receives the lifting wheel 54 of an entering carrier and lowers itswork arm 46). After the arm has been lowered, rail section 86 ismechanically moved to an inoperative position so that the arm of anentering carrier will not be raised on the next upward movement of theelevator.

Rail section 87 operates in a reverse manner. it receives the liftingwheel of a carrier advanced to the last station, raises the work arm ofthis carrier on the next upward movement of the elevator and, as theelevator returns to lowered position, swings to pass the lifting wheelof a following carrier advanced to the last station.

A system of mechanical stops is provided to prevent travel of the freecarriers 29 at stations where movable elevator rail sections areemployed. The rail section 86 at the entering station is equipped with amechanical stop 88 (Fig. 1) on its rail surface for contact by thecarrier lifting wheel 54. At the last station where movable rail section87 is employed, an overtravel stop 96 (Fig. 2) is secured to the side ofthe outer rail member 26. A pin 91 projects downwardly from the worksupporting carriage, and when this carriage is in lowered position, pin91 extends through a hole 92 in the carrier base member 34) forengagement with the stop 90.

Preferably the machine is designed so that a carrier is advanced onto amovable elevator rail section 86 when the shuttle reaches the end of itsdriving stroke. The shuttle is held in this position while the elevatorlowers and thus the engagement between the carrier pawl 32 and a shuttlepusher member 68 acts to positively prevent the carrier from coastingbackward off the movable rail section. Such backward movement of thecarrier is we vented on a movable elevator rail section 87 by a stop 94secured to the upper rail surface thereof. The lower position of theelevator rail is sufficiently below the carrier lifting wheels 54 for alifting wheel to clear this stop 94 when the carrier is advanced. Thissystem of stops gives positive control over the increment of carriertravel to transfer stations and hence also contributes to increasing theallowable rate of shuttle movement with consequent decrease in transfertime.

The general construction of the machine is relatively simple incomparison with other known machines of this type. More important is thefact that the carrier supporting and driving arrangement results in agreat degree of flexibility for a machine having certain basicstructure. Without changing this basic structure the number of car riersemployed can be varied, the maximum increment of carrier advance can beeasily varied (by changing the stroke or effective stroke of the shuttleactuating cylinder), the increment of carrier advance can be varied bychanging the location of tripping cams, and the number of carrierssimultaneously occupying a multistation treating area can be varied toobtain the maximum capacity from the machine.

The size of a machine of given capacity is reduced because the maximumnumber of carriers can be used.

While preferred embodiments have been described above in detail, it willbe understood that numerous modifications might be resorted to withoutdeparting from the scope of my invention as defined in the followingclaims:

I claim:

1. A work processing machine of the type having a plurality of worktreating locations such as tanks, a plurality of carriers each includinga vertically movable work supporting member, elevator means for movingselected work supporting members vertically, and wherein at least one ofthe work treating locations has a greater length in the direction ofcarrier travel than another and sufiicient to provide a plurality ofcarrier stations; an improved construction for varying the spacingbetween adjacent carriers so that the maximum number of carriers can besimultaneously positioned at. a particular work location, comprisingtrack means on which said carriers are each supported for free movementin a horizontal path of travel, a series of spaced pusher membersmounted for reciprocating horizontal movement adjacent to the path ofcarrier travel, means for reciprocating said pusher members in unison ona driving stroke at least equal in length to the longest increment oftravel required for advancing a carrier from a treating location to asuccessive treating location, a driven member on each carrier engageableby one of said pusher members, and tripping means for disengaging saidpusher and driven members to define a shorter increment of carriertravel at least at a treating location of suflicient length tosimultaneously accommodate more than one carrier, said tripping meansbeing mounted adjacent to the path of movement of said pusher and drivenmembers for actuation in response to the advance of a carrier by apusher member to the position defined by the location of said trippingmeans along the path of travel.

2. A work processing machine according to claim 1 wherein said trackmeans comprise vertically aligned upper and lower rail members, meansfor supporting each carrier on one of said rail members and means forguiding each carrier on both of said rail members, said guiding meansincluding a member secured to the carrier for frictional engagement withat least one of said rail members.

3. A work processing machine according to claim 1 wherein a shuttlemember is mounted for horizontal reciprocating movement adjacent to thepath of carrier travel defined by said track means, said pusher membersbeing secured to said shuttle member, said carrier driven members eachcomprising a pawl secured to each carrier for pivotal movement to adisengaged position in response to return movement of said pushermembers and additionally in response to actuation of said trippingmeans.

4. A work processing machine according to claim 3 wherein said trippingmeans comprises a member mounted for pivotal movement at a particularlocation along the path of travel, means carried by said shuttle andsaid tripping member for producing pivotal movement of the latter uponthe completion of a given amount of driving movement of said shuttle,and means for moving said pawl to disengaged position upon pivotalmovement of said tripping member.

5. A work processing machine according to claim 3 wherein said shuttlemember is mounted below said track means, the said pusher members ofsaid shuttle being positioned in approximate vertical alignment with thecenter line of said track means.

6. A work processing machine according to claim 1 further characterizedby means for positively preventing over-travel of a carrier advanced byone of said pusher members when the work supporting member of suchcarrier is in lowered position comprising a pin vertically movable withsaid Work supporting member and a fixed stop engageable by said pin whensaid work supporting member is in lowered position.

7. A work processing machine according to claim 1 wherein the treatinglocations are arranged around a continuous loop path of travel andcharacterized by said series of equally spaced pusher members beingmounted along a pair of shuttles positioned on either side of said loop,flexible propelling members interconnecting the ends of said shuttles,said flexible members each being trained about a sprocket mounted on avertical axis, oscillating pusher means for propelling a carrier aroundthe end portions of said loop from one shuttle to the other including apusher member mounted for movement on an axis eccentric to the saidsprocket axis and driving means for oscillating said pusher member inresponse to oscillation of said sprocket, the distance between the axesof said sprockets being greater than the distance between the axes ofsaid pusher members.

8. A work processing machine according to claim 7 wherein the drivingmeans for oscillating said pusher member includes a reduction betweensaid sprocket and pusher member.

9. In a work processing machine having a plurality of work processingstations, the combination of a plurality of carriers, means supportingeach of said carriers for free horizontal travel, and carrier propellingmeans comprising a series of spaced pusher members, means mounting saidpusher members for horizontal movement in unison adjacent the path ofcarrier travel, a driven member on each carrier engageable by one ofsaid pusher members for driving such carrier in one direction ofmovement of said pusher member, means for reciprocating said pushermembers on a driving stroke, at least some of said work stations havingtripping cam means mounted adjacent thereto and means for actuating saidtripping cam means to disengage said pusher and driven members beforesaid pusher members reach the end of their driving stroke.

10. In a work processing machine having a plurality of work stations,the combination of a plurality of carriers, vertically aligned upper andlower tracks, means for supporting each carrier on one of said tracksfor free movement thereon, means for guiding each carrier on both upperand lower tracks, carrier propelling means comprising a series of pushermembers, means mounting said pusher members for horizontal movement inunison in approximate vertical alignment with said tracks, a drivenmember on each carrier engageable by one of said pusher members fordriving such carrier in one direction, means for reciprocating saidpusher members on a driving stroke and a return stroke, and means atleast at some of said work stations for disengaging a carrier dn'venmember from a pusher member before the end of said driving stroke.

11. A work processing machine according to claim 10 wherein said meansfor guiding each carrier includes a pair of vertical rail surfaces oneach of said tracks and means on each carrier engageable with saidvertical rail surfaces.

12. A work processing machine according to claim 11 wherein theengagement between each carrier and said vertical rail surfaces is ofthe sliding type.

References Cited in the file of this patent UNITED STATES PATENTS2,650,600 Davis Sept. 1, 1953 2,654,462 Todd Oct. 6, 1953

